Tape recorder

ABSTRACT

A tape recorder wherein one end of a tape FF lever is engaged with a pinch roller-supporting board when the tape FF lever is rotated for the fast forward (FF) or rewind (REW) run of a cassette tape to effect the rotation of the pinch roller-supporting board, thereby retracting a pinch roller to a position where the pinch roller does not contact a tape surface; and, where the FF or REW run of the cassette tape is brought to an end, an automatic reverse plunger is driven for the rotation of the pinch roller-supporting board to disengage the pinch roller-supporting board from the tape FF lever, thereby releasing the FF or REW lock.

BACKGROUND OF THE INVENTION

This invention relates to a tape recorder for effecting the fast forward(FF) and rewind (REW) run of a cassette tape.

With a tape recorder allowing for the FF and REW run of the cassettetape, it is considered necessary to remove a pinch roller from a capstanshaft at the time of the FF and REW run of the cassette tape and retractthe pinch roller to a position in which the pinch roller does notcontact a tape surface. If, in this case, the tape recorder can belocked to the FF or REW mode of operation with the pinch rollerretracted, then it eliminates the necessity for the operator to manuallyset a tape FF lever in the prescribed position, thereby favorablysimplifying the operation of the tape recorder. However, the prior arttape recorder which uses a special mechanism for locking it to the FF orREW mode has the drawback that many parts have to be provided, resultingin the complication of the whole arrangement of the tape recorder. Wherea cassette tape is taken up to the end with a tape recorder lockable tothe FF or REW mode, it is desired to let the FF or REW lock beautomatically released or bring the tape recorder to rest or render itready for the reproduction mode by the automatic reverse operation.However, the prior art tape recorder uses a very complicated mechanismfor releasing the FF or REW lock, involves a large number of parts andconsequently occupies a considerable space.

SUMMARY OF THE INVENTION

It is therefore a first object of this invention to provide a taperecorder which can be locked to the FF or REW mode with great easewithout increasing the number of parts.

A second object of the invention is to provide a tape recorder which canbe unlocked from the FF or REW mode by a simple arrangement.

To attain the first object, this invention causes one end of a tape FFlever to be engaged with a pinch roller-supporting board when the tapeFF lever is rotated, thereby retracting the pinch roller to a positionin which the pinch roller does not contact a tape surface. When engagedwith the FF lever, the pinch roller-supporting board is locked to the FFor REW mode. As a result, the lever is also locked to the FF or REWmode, thereby enabling the FF or REW lock to be sustained, even when theoperator takes his hand off the tape FF lever.

To realize the second object, this invention causes one end of a tape FFlever to be engaged with a pinch roller-supporting board when the tapeFF lever is rotated, thereby effecting the FF or REW lock. When the FFor REW operation proceeds to the end of a cassette tape, then anautomatic reverse plunger is actuated to rotate the pinchroller-supporting board, thereby disengaging the pinch roller from thetape FF lever to release the FF or REW lock.

The above and further objects and novel features of the invention willmore fully appear from the following detailed description when the sameis read in connection with the accompanying drawing. It is to beexpressly understood, however, that the drawing is for purpose ofillustration only and is not intended as a definition of the limits ofthe invention.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a plan view of a tape recorder according to this invention,with the covering case taken off;

FIG. 2 is an exploded perspective view of a reel rest;

FIG. 3 is a longitudinal sectional view of an assembled reel rest;

FIG. 4 is a schematic top plan view showing the mechanical relationshipof a power transmitting mechanism and one-way clutch mechanism;

FIG. 5 is a block circuit diagram indicating the action of amagnetism-sensitive element;

FIG. 6 is a top plan view showing the mechanical relationship of aplunger, cam board, pinch roller-supporting board and tape fast forward(hereinafter abbreviated as "FF") lever;

FIG. 7 is a top plan view indicating the action of the cam board;

FIG. 8 is a top plan view showing the action of a head-supporting board;

FIG. 9 is a fractional front view on line IX--IX of FIG. 8 of thehead-supporting board;

FIG. 10 is a top plan view indicating the mechanical relationship of aneccentric pin and the head-supporting board;

FIG. 11 is a sectional view on line XI--XI of FIG. 10;

FIG. 12 is a top plan view showing the mechanical relationship of thehead-supporting board and a motor polarity changeover switch;

FIG. 13 is a sectional view on line XIII--XIII of FIG. 12;

FIGS. 14A to 14D are block diagrams indicating the action of the motorpolarity changeover switch;

FIG. 14E is a schematic servo circuit for the motor polarity changeoverswitch;

FIG. 15 is a top plan view showing the mechanical relationship of theplunger, cam board, pinch roller-supporting board, tape FF lever andhead-supporting board;

FIG. 16 is a top plan view showing the positions of the pinchroller-supporting board and head-supporting board when the tape FF leveris actuated;

FIG. 17 is a right side view of a locking mechanism, before anengagement lever is pressed, showing that a movable chassis is in arising position;

FIG. 18 is a right side view of the locking mechanism, while theengagement lever is pressed;

FIG. 19 is a perspective view of the locking mechanism, after theengagement lever is pressed, showing that the movable chassis is in afalling position;

FIG. 20 is a perspective view of an erase head, before a push lever ispressed;

FIG. 21 is a perspective view of the erase head, when a recording modehas been arranged by pressing the push lever;

FIG. 22 is a fractional perspective view of the push lever in which aprogram switch is mounted;

FIG. 23 is a top plan view of a stopper board, before the push lever ispressed;

FIG. 24 is a top plan view of the stopper board, after the push lever ispressed;

FIG. 25 is a fragmental side view of a cassette located by locatingpins;

FIG. 26 is a bottom plan view showing the mechanical relationship of amain switch of an electric circuit and the movable chassis;

FIG. 27 is a side view on line XXVII--XXVII of FIG. 26;

FIG. 28 is a perspective view of a tape recorder case;

FIG. 29 is a perspective view of the upper half of the case showing theinside thereof;

FIG. 30 is a block circuit diagram showing the action of an FF switchand a program switch; and

FIG. 31 is a block diagram showing the operation of an automatic reverseprevention switch.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

There will now be described by reference to the accompanying drawing anautomatic reverse tape recorder embodying this invention.

Referring to FIG. 1, a tape recorder according to this inventioncomprises a movable chassis 16 rotatably fitted to a fixed chassis 14 bymeans of a pair of rotation pins 11, 12. As in the Staar system, themovable chassis 16 rises upwardly in a rotated state when a lockingmechanism 20 is released by the insertion of a cassette 18. When themovable chassis 16 rises, the cassette 18 is supported on a reelmechanism 22. A rotation torque is transmitted from a motor 24 to thereel mechanism 22 by means of a motive power-transmitting mechanism 26.A head-supporting board 30 carrying a pair of recording-reproductionheads 27, 28 is rotatably fitted to the fixed chassis 14. These pairedrecording-reproduction heads 27, 28 may be each of the 4-track 2-channeltype and are spaced from the rotation center of a head-supporting board30 at the same distance. A rotatable cam board 32 designed to rotate thehead-supporting board 30 for the alternate push of the pairedrecording-reproduction heads and a plunger mechanism 34 are also mountedon the fixed chassis 14. A rotatable pinch roller-supporting board 40 isalso mounted on the fixed chassis 14 at a point above thehead-supporting board 30. This pinch roller-supporting board 40 isprovided at one end with a pinch roller 38 for clamping a tape with theaid of a capstan shaft 36 set on the movable chassis 16. A tape FF lever42 is also provided on the fixed chassis 14. When the pinchroller-supporting board 40 is rotated to retract the pinch roller 38,then the tape FF lever 42 effects the quick run of a cassette tape. Anerase head 44 is retractively set on the fixed chassis 14, which is alsofitted with an erase head changeover mechanism 46 for controlling theforward and backward movements of the erase head 44. In addition to theabove-mentioned mechanical parts, a head circuit changeover switch 48and motor polarity changeover switch 50 are mounted on a printed circuitboard (not shown) disposed below the fixed chassis 14. Further, a taperunning direction-instructing switch 52 is mounted on the fixed chassis14. There will now be described the constituent parts of the aforesaidvarious mechanisms and other mechanisms.

Now, viewed from the direction in which the cassette is inserted intothe tape recorder, that is, the right side of FIG. 1, the direction inwhich a tape is run from the left to the right is referred to as "aforward direction". The opposite direction in which the tape travelsfrom the right to the left is referred to as "a reverse direction".

As apparent from FIG. 1, the reel mechanism 22 comprises a pair of reelrests 60, 160, which obviously act as a tape feed or a tape takeupmember alternately in accordance with the direction in which the motoris driven. Description is now given of the reel rest 60 acting, forexample, as a tape feed member at the time of the forward run of a tape.

As seen from FIGS. 2 and 3, the reel rest 60 comprises a threaded andflanged reel shaft 62 provided with an axially extending slit, and areel base 66 having a key (not shown) engageable with said slit, andfitted to the reel shaft 62 by means of one-way clutch mechanism 64. Amagnetic ring 68 provided with a plurality of alternately arranged N andS poles is fitted around the peripheral wall of the reel base 66. Adrive pawl 72 is threadedly engaged with the external or male threadportion of the reel shaft 62 by means of a compression spring 70. Thereel shaft 62 is loosely fitted around the peripheral wall of a gearshaft 75 of a reel gear 74 constituting part of the later describedmotive power-transmitting mechanism 26. The reel gear 74 is securelyfitted to the gear shaft 75 by means of a collar 76. A nut 78 (FIG. 3)is threadedly engaged with the male thread portion of the lower endsection of the gear shaft 75 to fix the reel rest 60 to the movablechassis 16. A snap ring 82 is fitted into an annular groove 80 (FIG. 2)formed in the peripheral wall of the free end of the gear shaft 75 tofix the reel base 66 to the reel shaft 62.

The one-way clutch mechanism 64 comprises a clutch plate 83, in theperipheral edge of which three spiral notches are cut out equiangularly,a felt plate 84 disposed between the clutch plate 83 and reel base 66,and three steel balls 86 (FIG. 2) received in the respective spiralnotches of the clutch plate 83. The steel balls are chosen to have sucha dimension that they can be loosely moved through a free space definedbetween the inner peripheral wall 87 of the reel gear 74 and the spiralnotches of the clutch plate 83.

As shown in FIG. 4, the reel rest 160 acting as a tape takeup member inthe above-mentioned case has the same construction as the aforesaid tapefeed reel rest 60, except that the spiral notches of the clutch plate 83extend in the opposite direction to those of said tape feed reel rest60, and the magnetic ring 68 is omitted. The constituent parts of thetape takeup reel rest 160 are denoted by reference numerals formed byadding the number 100 to the reference numerals representing thecorresponding constituent parts of the tape feed reel rest 60.

With the automatic reverse tape recorder of this invention, the rotationtorque of the motor 24 is transmitted by means of a motor pulley 90(FIG. 4) to the capstan 36 and reel shafts 62, 162 through the motivepower-transmitting mechanism 26 consisting of a series of gears, withoutpassing through an idler lever, etc. as is the case with the prior artautomatic reverse tape recorder. As shown in FIG. 4, the motivepower-transmitting mechanism 26 comprises a capstan gear 92 fitted tothe capstan shaft 36, a pair of reel gears 74, 174 respectively fittedto the reel shafts 62, 162, and an intermediate gear 94 positionedbetween the capstan gear 92 on one hand and reel gears 74, 174 on theother. The rotation torque of the motor 24 is transmitted by means ofthe motor pulley 90 to the capstan 36 through a flywheel 96 and thenceto the reel gears 74, 174 through the capstan gear 92 and intermediategear 94. The rim of the flywheel 96 is fitted with a rubber tire 98.

When the motor pulley 90 of the motor 24 is rotated counterclockwise ofFIG. 4, then the capstan 36 and reel gears 74, 174 are all rotatedclockwise. When, with the tape feed reel rest 60, the reel gear 74 isrotated clockwise, then the steel balls 86 run away toward the largerspace due to the contact with the inner peripheral wall 87 of the reelgear 74 and are rotated idly between the inner peripheral wall 87 andclutch plate 83, giving rise to no friction therebetween. As a result,the clutch plate 83 and consequently the reel base 66 and reel shaft 62are obviously not rotated. Conversely with the tape takeup reel 160, thesteel balls 186 tightly contact the inner peripheral wall 187 of thereel gear 174 and are moved toward the small space to perform a wedgingaction. Since, at this time, a frictional force appears between theinner peripheral wall 187 of the reel gear 174 and the clutch plate 183,the steel balls 186 cause the clutch plate 183 to be rotated clockwise.The rotation of the clutch plate 183 leads to the rotation of the reelbase 166 by means of the felt plate 184. As a result, the reel rest 160takes up a tape.

When the motor pulley 90 is rotated clockwise (not shown), then theclutch plate 83, felt plate 84, and reel base 66 are rotated by thereverse operation from that described above, causing the reel rest 60 totake up a tape.

As mentioned above, the motive power-transmitting mechanism 26 comprisesthe capstan gear 92, intermediate gear 94, and reel gears 74, 174. Evenif the reel gears 74, 174 corresponding to the tape takeup reel rest 60and tape feed reel rest 160 are rotated at the same time, the one-wayclutch mechanism 64, 164 allows only the reel rest 60 or 160 acting as atape takeup member to be rotated. When, therefore, the rotatingdirection of the single motor 24 is reversed, the forward or reverse runof a tape can be easily ensured.

The rotation of the motor 24 is reversed at the detection of a tape endand further as often as required. A magnetism-sensitive element 100 isprovided, as shown in FIGS. 1 and 4, adjacent to the magnetic ring 68.The magnetism-sensitive element 100 and the magnetic ring 68 constitutetape end detecting means. This magnetism-sensitive element 100 causeseither of the paired recording-reproduction heads to be pushed when thereversal of the run of the motor 24 is detected. To describe it ingreater detail, the magnetism-sensitive element 100 detects changes inthe waveform of pulses issued from the pulse-generating magnetic ring 68provided with a plurality of alternately arranged N and S poles, andproduces an output signal. This output signal is successively processed,as shown in FIG. 5, by a signal-processing circuit 102, logic circuit104, and plunger driving circuit 106 in the order mentioned, eventuallyactuating the plunger mechanism. As a result, the head-supporting board30 is rotated, causing either of the paired recording-reproduction headsto be pushed alternately. The pulse-generating magnetic ring 68 forissuing pulses to the magnetism-sensitive element 100 is fitted to theperipheral wall of the reel body 64. However, the motor pulley 90 may beconcurrently used as a magnetic ring. This arrangement reduces thenumber of parts required and facilitates the assembly of the wholeautomatic reverse tape recorder. In such case the magnetism-sensitiveelement 100 should obviously be set adjacent to the motor pulley 90.

As seen from FIGS. 1 and 6, the plunger mechanism 34 comprises a plunger110 and plunger body 112 which is connected to a plunger-driving circuit106 and through which a plunger reciprocates. The free end of theplunger 110 has a flat upper surface 113, which is fitted with one endof a coupling board 114 for transmitting the reciprocation of theplunger 110 to a cam board 32 for rotating a heat-supporting board 30.To describe it in greater detail, a pin 116 erected at one end of thecoupling board 114 extends through a hole formed in the flat surface 113of the plunger 110. The coupling board 114 is fitted to the plunger 110by means of a snap ring (not shown). The pin 116 passes upward throughthe coupling board 114. A plunger arm 118 having a long groove which isdisposed above the coupling board 114 and allows for the reciprocationof the pin 116 is movably mounted on the fixed chassis 14 adjacent tothe plunger 110. A guide groove 120 having a triangular cross section isformed in the surface of the plunger 110 to guide its reciprocation in astate preventing it from being rotated.

As will be apparent from FIG. 6, a pinch roller-supporting board 40 isdisposed between the plunger arm 118 and coupling board 114. The pinchroller-supporting board 40 is mounted on the fixed chassis 14 by causingthe upwardly extending integral collar of the supporting board 40 to beloosely fitted around a shaft 121 erected on the fixed chassis 14 andalso fitting a snap ring to the shaft 121. A torsion coil spring 188 isfitted around the shaft 121 to impart a counterclockwise urging force tothe pinch roller-supporting board 40. One end of the torsion coil spring188 is pressed against the lateral face of an eccentric pin 197(described later). The pinch roller 38 is rotatably fitted to one end ofthe pinch roller-supporting board 40, the other end of which is providedwith a notch 123, against which the pin 122 of the tape FF lever 42 ispressed. A projecting attachment 124 is mounted on the pinchroller-supporting board 40 between the cam board 32 and plunger arm 118.Erected on the upper surface of the projecting attachment 124 is a pin126 fitted into a groove formed in the two-pronged free end of theplunger arm 118. As seen from FIG. 6, the pinch roller-supporting board40 holding the pinch roller 38 has one end shaped like the letter T,both ends of whose bar are constituted by downwardly bent portions 128,129.

To avoid the complication of the drawing, the shaft and pin acting as arotation center are particularly marked with the symbol in drawingsother than FIG. 1.

As is apparent from FIG. 7, a downwardly extending pin 130 is erected atthe other end of the coupling board 114. A tension coil spring 131 isstretched between the pin 130 and fixed chassis 14. This tension coilspring 131 presses the pin 130 against the lateral wall of theheart-shaped cam groove 132 of the cam board 32. The heart-shaped camgroove 132 comprises a pair of lobes 135, 136 and a pair of corners 133,134. Both lobes 135, 136 jointly define a V-shaped junction 137. When atape is run in the forward direction and the recording-reproduction head27 is pushed, the pin 130 is pressed against the lobe 133.

A larger pin 138 and smaller pin 139 project from the upper surface ofthe cam board 32. A torsion coil spring 142 acting as a toggle spring isstretched between the larger pin 138 and a pin 140 erected on the fixedchassis 14. The cam board 32 is rotatably fitted to the fixed chassis 14by means of a rotating pin 144. In the condition indicated in FIG. 7,the junction 137 of the paired lobes 135, 136 is set below an imaginaryline extending between the pin 144 acting as a rotation center and thepin 130. The cam board 32 comprises an integrally formed two-prongprojecting attachment 148. A movable contact 149 of a tape rundirection-instructing switch 52 is fitted into a long groove of theprojecting attachment 148. The switch 52 comprises a pair of fixedcontacts 150, 151 with a movable contact 149 set therebetween. Aconnection between the movable contact 149 and either of the pairedfixed contacts 150, 151 closes the tape run direction-instructingcircuit, causing either of a pair of lamps (not shown) indicating theforward and backward runs of a tape, to be lighted.

The head-supporting board 30 rotated by the cam board 32 comprises, asshown in FIGS. 8 and 9, an adjustment leaf spring 190, both ends ofwhich are turned slighted upward. The recording-reproduction heads 27,28 (only 27 is indicated to avoid the complication of representation)are set above both upturned ends of the adjustment leaf spring 190. Therecording-reproduction head 27 is set in place by mounting a fittingboard 192 attached to the underside of the recording-reproduction head27 on one of both upturned ends of the adjustment leaf spring 190, andfitting both ends of the fitting board 192 to the head-supporting board30 by means of screws 193, 194. The inclination and displacement of therecording-reproduction head 27 are prevented by holding two washers 195to define the level at which the recording-reproduction head 27 is to befixed and controlling the threaded engagement of the other screw 194.The leaf spring 190 slightly turned upward at both ends enables theazimuth of the recording-reproduction head to be adjusted easily andover a broad range. The head-supporting board 30 is fitted to the fixedchassis 14 by means of a screw 196 in a state rotatable about the screw196. A pair of eccentric pins 197, 198 are equidistantly arranged onboth sides of the rotatable screw 196 to adjust the position of therecording-reproduction head when pushed at the rotation of thehead-supporting board 30. As shown in FIGS. 10 and 11, the eccentric pin198 has its upper surface provided with a slot and its lower portionformed into a male-threaded screw. The slotted surface and male-threadedlower portion are concentrically arranged. An annular groove 199 isformed at the central part of the eccentric pin 198, with the peripheralwall of the groove 199 pressed against the lateral side of thehead-supporting board 30. The center line of the eccentric pin 198 isdisplaced from that of the annular groove 199 for a distance e. Since,as mentioned above, the annular groove 199 is displaced from themale-threaded lower portion of the eccentric pin 198 fitted to the fixedchassis 14, the rotation of the slotted surface of the eccentric pin 198causes that plane of the eccentric pin 198 which abuts against thehead-supporting board 30 to be widely displaced, although the eccentricpin itself remains unchanged in position. Accordingly, the horizontallypushed position of the recording-reproduction head 27 or 28 can bereliably adjusted over a broad range without increasing the free spaceoccupied by the eccentric pin 198. The head-supporting board 30 insertedinto the annular groove 199 has its height defined by the condition inwhich the eccentric pin 198 is threadedly engaged with the fixed chassis14. Therefore, the level at which the recording-reproduction head 27 or28 is set above the head-supporting board 30 can be adjusted by theannular groove 199 of the eccentric pin 198. Also the vertical shakingof the head-supporting board 30 itself can be prevented. Anothereccentric pin 197 is obviously shaped like the eccentric pin 198.

As apparent from FIG. 8, the head-supporting board 30 comprises anintegrally formed two-pronged protuberance 200 engageable with the pin139 erected on the cam board 32, and lever-like projections 202, 203formed on both sides of the rotation center of the head-supporting board30. These lever-like projections 202, 203 act as actuating levers foractuating the head circuit changeover switch 48 or motor polaritychangeover switch 50.

There will now be described the motor polarity changeover switch 50 byreference to FIGS. 12 and 13. This motor polarity changeover switch 50comprises one set of a single movable contact 204 and paired fixedcontacts 206, 207 and another set of a single movable contact 204 andpaired fixed contacts 206, 207. When the recording-reproduction head 27,for example, is pushed, the movable contact 204 having an elasticity ofits own has the ability of touching one fixed contact 206 but not thelever-like projection 203. When the head-supporting board 30 is rotatedclockwise of FIG. 8 to push the other recording-reproduction head 28,then the movable contact 204 is forcefully moved to touch the otherfixed contact 207 by means of the lever-like projection 203. The headcircuit changeover switch 48 has the same property and is operated inthe same manner as the motor polarity changeover switch 50. In theforegoing embodiment, the head circuit changeover switch 48, motorpolarity changeover switch 50 and tape run direction-instructing switch52 are separately arranged. However, it is possible to provide a singleswitch designed concurrently to changeover the head circuit and motorpolarity and also instruct the tape run direction.

As illustrated in FIGS. 14A to 14D, the electric circuit of the motorpolarity changeover switch 50 can drive a motor in the normal or reversedirection by means of a motor control circuit 108. The constant rotationspeed of a motor for both forward and reverse reproductions can beeffected by making a comparison between a value obtained by detectingthe actual number of rotations of the motor and a control target valuedesigned to set the motor rotation at the prescribed speed and carryingout such control (namely, servo control) as minimizes a possibledifference resulting from the comparison. A servo circuit used for thisparticular purpose may be of the known type shown in FIG. 14E. For theabove-mentioned object, the switch 51 is released as shown in FIGS. 14A,14B to apply servo control, thereby effecting the forward and reverserotations with the rotation speed of a motor always rendered constant.The acceleration of the rotation speed of a motor for the FF and REWmodes of a tape run is carried out by setting a control value at ahigher level than a maximum number of rotations of a motor, andreleasing the servo control to let the motor run at a maximum speed. Tothis end, the switch 51 is closed as shown in FIGS. 14C and 14D toeffect the FF and REW modes of a tape run. As mentioned above, the servocontrol is applied or stopped by the changeover of the operation of theswitch 51, and the operation of the motor polarity changeover switch 50is shifted, thereby making it possible to effect the forward and reversereproductions, and the FF and REW modes of a tape run simply by drivinga single motor. Therefore, the object of letting the single motor run ata constant speed, and controlling its high speed normal and reverserotations is attained by a simple arrangement. An automatic reverse taperecorder embodying this invention which is free from a complicatedmechanical arrangement can be operated with high reliability andmanufactured at low cost. Where the motor is to be driven in the reversedirection, it is preferred that the motor be started a prescribed lengthof time after the end of its normal run in order to prevent its possibledamage occurring at the start of its reverse rotation.

As shown in FIG. 6, a tape FF lever 42 is rotatably fitted by means of asnap ring to a rotatable pin 210 mounted on the fixed chassis 14. Thistape FF lever 42 is provided at one end with a pin 122 engageable with anotch 123 formed in the pinch roller-supporting board 40. The tape FFlever 42 comprises an attachment 212 which is bent vertically downward(toward the backside of the drawing) and formed at the outer end of thetape FF lever 42, triangular hole 214 and elongated groove 216. Thelever attachment 212 projects out of a case 218 in which the fixedchassis 14 and movable chassis 16 are received. Disposed in thetriangular hole 214 is a pin 224 erected at the free end of a couplingboard 222 movably fitted to the fixed chassis 14 by means of a rotatablepin 220. One end of a torsion coil spring 226 wound about the rotatablepin 220 is pressed against the pin 224 and so erected as to project outof the triangular hole 214. The pin 220 is urged toward the apex 227 ofthe triangular hole 214, thereby ensuring the neutral position of thetape FF lever 42. When the lever attachment 212 is rotated in thedirection of A indicated in FIG. 6, then the pin 224 is pressed againstthe corner 229 of the triangular hole 214. When the lever attachment 212is rotated in the direction of B indicated in FIG. 6, then the pin 224abuts against the corner 228 of the triangular hole 214. A movablecontact 232 of a motor fast drive switch 230 is fitted into theelongated groove 216. While remaining in a neutral position as shown inFIG. 6, the movable contact 232 touches neither of the fixed contacts233, 234.

There will now be described the alternate push of therecording-reproduction heads 27, 28 by the rotation of thehead-supporting board 30. Now let it be assumed that therecording-reproduction head 27 is pushed and a tape is running in theforward direction. If, in this case, the run of the motor 24 is reversedeither by hand, if necessary, or automatically by the detection of atape end, then the magnetism-sensitive element 100 detects changes inthe waveform of pulses issued from the magnetic ring 68. As a result,the plunger 110 is moved inwardly for the prescribed distance againstthe urging force of the tension spring 131 by the joint action of thesignal-processing circuit 102, logic circuit 104 and plunger drivecircuit 106. When the recording-reproduction head 27 is pushed, then thepin 130 of the coupling board 114 is urged as shown in FIG. 7, to thecorner 133 of the heart-shaped cam groove 132. As a result, the junction137 of the paired lobes 135, 136 is positioned below an imaginary lineextending between the pin 130 and the rotation center 144 of the camboard 32. When, therefore, the plunger 110 is moved inwardly, then thepin 130 of the coupling board 114 moving with the plunger 110 is guidedthrough the right lobe 135 of the heart-shaped cam groove 132 to pressthe end wall of the right lobe 135, thereby causing the cam board 32 tobe rotated counterclockwise about the rotation center 144. When the camboard 32 is rotated counterclockwise, the movable contact 149 is pressedagainst the other fixed contact 151 by means of the two-prongedprojection 148. As a result, a display lamp indicating the reverse run(right to left run) of a tape is lighted. With the counterclockwiserotation of the cam board 32, the pin 139 of the cam board 32 is engagedwith the two-pronged projection 200. As a result, the head-supportingboard 30 is rotated clockwise about the rotation center 196 (FIG. 8),until the board 30 touches the eccentric pin 197, thereby causing therecording-reproduction head 28 to be pushed. This eccentric pin 197 isconstructed in the same manner as the eccentric pin 198 and can adjustthe pushed position of the recording-reproduction head 28 and the levelat which the head 28 is to be fitted. As is apparent from FIG. 8, whenthe head-supporting board 30 is rotated clockwise, the lever-likeprojections 202, 203, respectively press against the movable contacts ofthe head circuit changeover switch 48 and motor polarity changeoverswitch 50, causing the movable contacts to abut against the other fixedcontact against their elastic force. The changeover of the operation ofthe switches 48, 50 establishes a head circuit for therecording-reproduction head 28 and reverses the polarity of the motor24.

After the recording-reproduction head 28 is pushed, the pin 130 of thecoupling board 114 is urged, as shown in FIG. 15, by the force of thetension spring 131 (FIG. 7) to be pressed against the lower corner 134of the heart-shaped cam groove 132. The coupling board 114 and plunger110 are brought back to a projecting position by the urging force of thetension spring 131. At this time, the V-shaped junction 137 of the lobes135, 136 of the heart-shaped cam groove 132 is set below an imaginaryline extending between the erected pin 130 and the rotation center 144of the cam board 32. When, therefore, the plunger 110 is moved inwardlyagainst the urging force of the tension spring 131, then the pin 130 isguided through the left lobe 136 of the heart-shaped cam groove 132 topress against the end wall of the lobe 136. Accordingly, the cam board32 is rotated clockwise, and the head-supporting board 30 is rotatedcounterclockwise, until said board 30 abuts against the eccentric pin198. Therefore, the recording-reproduction head 27 shown in FIG. 8 isagain brought to a projecting state. At this time the coupling board 114occupies the position indicated in FIG. 7.

The fast forwarding of a tape during its forward and reverse runs iseffected by the rotation of the tape FF lever about the rotation center210 (FIG. 6). Referring to FIG. 6, the REW operation during the forwardrun of a tape is carried out by rotating the lever attachment 212 in thedirection A. When the lever attachment 212 is rotated in the directionof A or B, the pin 224 is shifted from the neutral position in which thepin 224 is pressed against the wall of the apex 227 of the triangularhole 214 to the tape FF position in which the pin 224 abuts against thecorner 229 or 228 of the triangular hole 214. When the lever attachment212 is rotated, as shown in FIG. 16, in the direction A for the REWoperation, then the pin 122 of the tape FF lever 42 is moved clockwisealong the surface of the left side portion of the notch 123 whileagainst the wall thereof. As a result, the pinch roller-supporting board40 is rotated clockwise about the rotation center 121 (FIG. 6), causingthe pinch roller 38 to be separated from the capstan 36. The downwardbent attachment 128 or 129 of the end portion of the pinchroller-supporting board 40 to which the pinch roller 38 is fitted isalways positioned very close to part of the head-supporting board 30even when the recording-reproduction head 27 or 28 is in a pushed state.The downward bent attachments 128, 129 are set at a level which is thesame as or lower than the head-supporting board 30. Referring to FIG.16, therefore, in which the recording-reproduction head 27 is pushed,the retraction of the pinch roller-supporting board 40 due to therotation of the lever attachment 212 in the direction A causes thedownward bent lever attachment 129 to abut against the head-supportingboard 30. As a result, the board 30 is slightly rotated clockwise aboutthe rotation center 196 (FIG. 8). At this time, the pushedrecording-reproduction head 27 is slightly retracted. A tape which isnot contacted by the retracted recording-reproduction head 27 can movefast forward smoothly. The tape FF lever 42, head-supporting board 30and pinch roller-supporting board 40 occupy the positions indicated inone dot-dash lines in FIG. 16, after the tape FF lever 42 is rotated inthe direction A. Under such condition, the pin 224 is pressed againstthe corner 229 of the triangular hole 214 (FIG. 15) by the urging forceof the torsion coil spring 188. When the tape FF lever 42 is rotated inthe direction B of FIG. 16 showing the pushed recording-reproductionhead 28, then the pin 122 is rotated counterclockwise along the surfaceof the right side portion of the notch 123, when pressing against thewall of the notch 123. As a result, the head-supporting board 30 isslightly rotated counterclockwise about the rotation center 196 (FIG. 8)to retract the recording-reproduction head 28. In this case representingthe REW operation, the pin 224 is pressed against the corner 228 of thetriangular hole 214 (FIG. 6). At this time, the lever attachment 212 isrotated in the same direction as that in which a tape is fast forwarded.If, therefore, the recording-reproduction head 27 is pushed, the REWoperation is carried out by rotating the lever attachment 212 in thedirection A, and the tape FF operation is effected by rotating the leverattachment 212 in the direction B. Conversely when therecording-reproduction head 28 is pushed, then the tape FF operation iscarried out by rotating the lever attachment 212 in the direction A, andthe REW operation is realized by rotating the lever attachment 212 inthe direction B.

As seen from FIG. 16 showing the lever attachment 212 rotated indirection B for the FF mode (as indicated in a two-dots dash line), thepinch roller-supporting board 40 is rotated clockwise as when the leverattachment 212 is rotated in direction A. At this time, the pin 122presses against the notch 123 by engagement therewith and is movedcounterclockwise along the right side portion of the notch 123. The pin224 is pressed to the corner 228. When the tape FF lever 42 is rotatedin direction A or B, then the pin 122 provided at one end of the tape FFlever 42 engages the notch 123 of the pinch roller-supporting board 40to retract the pinch roller 38. The urging force of the torsion spring188 acting on the pinch roller-supporting board 40 is transmitted fromthe notch 123 to the pin 122 to securely set the tape FF lever 42 in theengaged position. Even if, therefore, the operator takes his hand offthe tape FF lever 42, the FF lever 42 is still kept in the engagedstate, thereby ensuring the FF or REW lock.

When the pin 122 is engaged with the notch 123 by rotating the tape FFlever 42 from the neutral position in direction A or B, then the tape FFlever 42 is pressed by the urging force of the torsion spring 188through the notch 123 and pin 122. When the tape FF lever 42 is rotated,for example, in direction A, then the urging force of the torsion spring188 passes through the rotation center 210 of the tape FF lever 42 oracts as a moment for causing the tape FF lever 42 to be rotatedclockwise about the rotation center 210. Therefore, the tape FF lever 42is kept in an engaged, that is, locked position, instead of regainingthe neutral position. Conversely when the tape FF lever 42 is rotated indirection B, then the urging force of the torsion spring 188 passesthrough the rotation center 210 or acts as a moment for causing the tapeFF lever 42 to be rotated counterclockwise about the rotation center210. As a result, the tape FF lever 42 remains locked instead ofregaining the neutral position.

The FF or REW lock in which the pin 122 of the tape FF lever 42 isengaged with the notch 123 of the pinch roller-supporting board 40 toretract the pinch roller, is effected when the urging force of thetorsion spring 188 is transmitted to the pin 122.

If the FF or REW mode of operation is carried on to the end of acassette tape, then the automatic reversal operation of the taperecorder starts by the action of the magnetism-sensitive element 100,with the resultant reciprocation of the plunger 110. The inward movementof the plunger 110 causes the pin 116 to be carried through theelongated groove of the plunger arm 118 up to the end, effecting thecounterclockwise rotation of the plunger arm 118 about the rotationcenter 240. The rotation torque of the plunger arm 118 is transmitted tothe pin 126 of the projecting attachment 124, causing the pinchroller-supporting board 40 to be rotated clockwise about the rotationcenter 121 against the urging force of the torsion spring 188. Thetorsion spring 226 normally urges the tape FF lever 42 to cause the pin224 to be pressed against the wall of the apex 227 of the triangularhole 214, namely, be set in a neutral position. The clockwise rotationof the pinch roller-supporting board 40 disengages the pin 122 of thetape FF lever 42 from the notch 123 of the pinch roller-supporting board40. As a result, the tape FF lever 42 is rotated to a neutral positionin which the pin 224 is urged by the torsion spring 226 to the wall ofthe apex 227 of the triangular hole 214. At this time, the pin 122 ispositioned at the central part of the notch 123.

As mentioned above, the FF or REW lock is released by reciprocating theplunger 110 by the automatic reverse operation of the tape recorder 10,converting the reciprocation of the plunger 110 into a rotation torque,and transmitting the rotation torque to the pinch roller-supportingboard 40 through the plunger arm 118 and finally disengaging the pinchroller-supporting board 40 from the tape FF lever 42. Theabove-mentioned process of releasing the FF-REW lock can be easilycarried out by the drive of the plunger resulting from the automaticreverse operation, thus saving the tape recorder from having to havecomplicated arrangement. The FF or REW lock can be effected by actuatingthe program switch as the need arises for the drive of the plunger 110without utilizing the automatic reverse operation.

As shown in FIG. 17, the locking mechanism 20 of the movable chassis 16comprises an engagement lever 242 reciprocably fitted to the fixedchassis 14 and engagement cam 244 rotatably fitted to the fixed chassis14. The engagement lever 242 has a pair of crosswise extending elongatedholes 245, 246. Guide pins 247, 248 fixed to a pair of attachmentsextending downward from the side walls of the fixed chassis 14 aredetachably inserted into the elongated holes 245, 246 by means of a snapring. The guide pins 247, 248 are pressed against the right side wallsof the corresponding elongated holes 245, 246 by the urging force of atension coil spring 249 stretched between the fixed chassis 14 andengagement lever 242. An engagement pin 250 is erected on the side wallof the engagement lever 242. The inner end of this engagement lever 242constitutes a cam surface 251. Reference numeral 252 of FIG. 17 denotesa push button fitted to the outer end of the engagement lever 242. Theengagement cam 244 is rotatably fitted to a bent attachment extendingupward from the side wall of the fixed chassis 14 by means of arotatable pin 254, and is urged counterclockwise of FIG. 17 by a torsioncoil spring 256 wound about the rotatable pin 254. The engagement cam244 comprises a pair of cam surfaces 257, 258 and three engagementgrooves 259, 260, 261. An engagement pin 264 engageable with theengagement groove 260 of the engagement cam 244 when the movable chassis16 is lifted, is provided on the lateral side of the movable chassis 16which faces the engagement cam 244. A movable guide roller 266 ismounted on the other lateral side of the movable chassis 16 which facesthe engagement lever 242. The guide roller 266 is loosely fitted aboutthe periphery of an erect pin 268. The movable chassis 16 is urgedupward by a tension spring 270 stretched between the movable chassis 16and a bent attachment extending upward from one lateral side of thefixed chassis 14. Another tension spring 270 is provided, as shown inFIG. 20, in a symmetric position on the other lateral side of the fixedchassis 14.

If the push button 252 is pressed to bring down the movable chassis 16,then the engagement lever 242 is pressed against the urging force of thetension spring 249, while being guided by the guide pins 247, 248, untilthe left end walls of the elongated holes 245, 246, respectively abutagainst the guide pins 247, 248. During the initial stage of the strokeby which the engagement lever 242 is pressed, the engagement pin 250 ofthe engagement lever 242 slides along the periphery of the cam surface257 of the engagement cam 244. As a result, the engagement cam 244 isrotated clockwise about the rotation center 254 against the urging forceof a torsion spring 256. The clockwise rotation of the engagement cam244 causes the engagement pin 264 of the movable chassis 16 to bedisengaged from the engagement groove 260 of the engagement cam 244. Atthis time, the cam surface 251 of the engagement lever 242 is pressedagainst the guide roller 266 of the movable chassis 16, causing themovable chassis 16 to be rotated against the urging force of the tensionspring 270 counterclockwise about the rotation center (FIG. 1), namely,to be pressed downward. Accordingly, the engagement pin 264 is broughtto a position facing the cam surface 258 (FIG. 18). When the stroke ofpressing the engagement lever 242 proceeds further, the guide roller 266is moved further downward along the cam surface 251 of the engagementlever 242 against the urging force of the tension spring 270. At thistime, the engagement pin 264 of the movable chassis 16 is guided alongthe cam surface 258. When the stroke of pressing the engagement lever242 is brought to an end, then the engagement pin 264 is inserted intothe engagement groove 261, thereby letting the tension spring 270 have afull urging force. As a result, the movable chassis 16 is brought to afallen position as shown in FIG. 19. The stroke of pressing theengagement lever 242 is stopped when the guide pins 247, 248,respectively abut against the left end walls of the elongated holes 245,246. At the end of the stroke, the engagement pin 250 is received in theengagement groove 259, causing the tension spring 249 to have a fullurging force.

When, in FIG. 19 showing the fallen movable chassis 16, a release lever278 movably mounted on the fixed chassis 14 by means of a rotatable pin276, is rotated by the insertion of a cassette, then the movable chassis16 is lifted. In other words, when inserted, the cassette presses anupward bent attachment 280 (FIG. 19) formed at one end of the releaselever 278. As a result, the release lever 278 is rotated clockwise abouta rotation center 276. The tip of the other end portion of the releaselever 278 is disposed fully apart from the rotation center 254 of theengagement cam 244, and one lateral side of the other end portion of therelease lever 278 is set adjacent to the lateral side of the engagementcam 244. The upward bent attachment 280 itself is fully removed from therotation center 276. Even if, therefore, the inserted cassette slightlypresses against the upward bent attachment 280, then a great rotationtorque is applied to the engagement cam 244. Accordingly, when theupward bent attachment 280 of release lever 278 is pressed, howeverslightly, by the inserted cassette, the engagement cam 244 isimmediately rotated clockwise of FIG. 19. As a result, the engagementpin 264 of the movable chassis 16 is released from the engagement groove261. At this time, the engagement pin 264 slides along the cam surface258 by the urging force of the tension spring 270 which has beenaccumulated by the stroke of pressing the engagement lever 242 to rotatethe engagement cam 244 and then is inserted into another engagementgroove 260. The movable chassis 16 is lifted with the movement of theengagement pin 264 and brought to rest when the engagement pin 264 isinserted into the engagement groove 260.

Like the tension spring 270, the tension spring 249 stretched betweenthe engagement lever 242 and fixed chassis 14 has its urging force fullyaccumulated during the stroke by which the engagement lever 242 ispressed. Therefore, a force for rotating the engagement cam 244clockwise is transmitted from the engagement pin 250 to the cam surface257. When the engagement pin 264 is released from the engagement groove261, the engagement cam 244 is rotated by an urging force transmittedfrom the tension spring 249 through the engagement pin 250, as well asby an urging force applied from the tension spring 270 to the engagementpin 264. As a result, the engagement pin 250 is brought back to a statedisengaged from the engagement groove 259. The engagement lever 240regains a projecting position by the fully accumulated urging force ofthe tension spring 249.

With the above-mentioned locking mechanism 20, the urging force of thetension spring 270 is accumulated by the stroke of pressing theengagement lever 242. The movable chassis 16 is lifted by theaccumulated urging force of the tension spring 270. Therefore, thepressing force applied by the insertion of a cassette well serves thepurpose, even if it is small. Therefore, it is unnecessary to apply agreat force to a cassette when it is inserted. When, therefore amechanically weak cassette such as a microcassette is fitted into therecording-reproduction apparatus, the movable chassis 16 can be liftedwithout damage to or destruction of such cassette. Further, twoengagement grooves 260, 261 are formed in a single engagement cam 244.The movable chassis 16 is lifted or lowered by the different modes ofengagement between the engagement pin 264 between the engagement grooves260, 261. This arrangement renders the construction of the lockingmechanism 20 simplified and compact, and provides a shockproofengagement. The movable chassis 16 is lifted by engagement between theengagement groove 260 and engagement pin 264. If, therefore, the tensionspring 270 used has a small tension constant, it is obviously possibleto let the spring 270 have a fully accumulated urging force when themovable chassis 16 is to be brought down.

While the recording-reproduction head 27 is pushed, as shown in FIG. 16,the lever-like projection 203 of the head-supporting board 30 is notdisposed above the engagement lever 242. When pressed, therefore, by astroke, the engagement lever 242 does not abut against the lever-likeprojection 203. In contrast, when the head-supporting board 30 isrotated clockwise to cause the recording-reproduction head 28 to bepushed, then the lever-like projection 203 protrudes beyond theengagement lever 242, as shown in FIG. 15. In this case, the projection203 is positioned adjacent to the forward wall of the stepped portion282 of the engagement lever 242 (FIG. 17). If, therefore, the engagementlever 242 is pressed to eject a cassette with the recording-reproductionhead 28 kept in a pushed state, then the stepped portion 282 of theengagement lever 242 presses the lever-like projection 203 to rotate thehead-supporting board 30 counterclockwise, thereby pushing the otherrecording-reproduction head 27. If the recording-reproduction head 27 ispushed, as described above, when the engagement lever 242 is pressed toeject a cassette, then the head 27 is left in situ. If therecording-reproduction head 28 is pushed when the engagement lever 242is pressed, then the recording-reproduction head 27 is now pushed by therotation of the head-supporting board 30. Therefore, therecording-reproduction head 27 never fails to be pushed after a cassetteis ejected. If the cassette is again inserted into the tape recorder 10in case of need, recording and reproduction can always be carried out bythe head 27.

As shown in FIGS. 1 and 20, the tape recorder 10 comprises an erase headoperation changeover mechanism 46 which pushes the erase head 44 at thetime of recording and retracts it at the time of reproduction. The taperecorder 10 is used as part of, for example, a car stereophonic system.The erase head operation changeover mechanism 46 is provided with anerase head operation changeover push lever 290 for actuating anamplifier switch (not shown). As seen from FIG. 20, the push lever 290has an elongated hole 292 formed in the upper surface and anotherelongated hole 293 provided on the lateral side. The pins 295, 296 ofthe fixed chassis 14 are loosely fitted into the elongated holes 292,293 by means of a snap ring. A tension coil spring 300 is stretchedbetween an upward bent attachment 297 provided on the lateral side ofthe push lever 290 and an upward bent attachment 298 formed on thelateral side of the fixed chassis 14. The pins 295, 296 are respectivelypressed against the left side walls of the elongated holes 292, 293 bythe urging force of the tension coil spring 300. The erase head 44 ismounted on a head-fitting board 304 by means of two screws 302, 303. Thehead-fitting board 304 is rotatably mounted on the fixed chassis 14 bymeans of a rotatable pin 306. One end of a torsion coil spring 308 woundabout the pin 306 is pressed against the screw 303, causing thehead-fitting board 304 to be urged clockwise. The screw 303 is pressedagainst a bent attachment 311 formed on the push lever 304. Since thetension coil spring 300 has a greater urging force than the torsion coilspring 308, the head-fitting board 304 is rotated counterclockwise, andthe erase head 44 is retracted, as shown in FIG. 20, at the fall of themovable chassis 16. An engagement pin 310 is fitted to the lateral sideof the push lever 290. Two notches 312, 313 are formed in the upper edgeof the lateral side of the movable chassis 16 for engagement with theengagement pin 310. The notch 312 is formed at such a point as allowsfor the engagement of the engagement pin 310, when the movable chassis16 is lifted without pressing the push lever 290. The other notch 313 isformed at such a point as allows for the engagement of the engagementpin 310, when the movable chassis 16 is lifted by pressing the pushlever 290 against the urging force of the tension coil spring 300, untilthe pins 295, 296 are respectively pressed against the right end wallsof the elongated holes 292, 293.

The push lever 290 has a projecting attachment 317 formed on the innerlateral wall. The projecting attachment 317 is fitted with the laterdescribed guide pin 324. An automatic reverse stop switch 315 fitted toa printed circuit board (not shown) is set inside of the projectingattachment 317. The automatic reverse stop switch 315 is a normallyclosed type provided in the plunger driving circuit 106, and is renderednonconducting when the push lever 290 is pressed inward. The switch 315has a movable contact disposed inside of the projecting attachment 317of the push lever 290. When the push lever 290 is pressed, theprojecting attachment 317 is pressed against the movable contact torelease it from the fixed contact, thereby rendering the switch 315nonconducting.

The engagement pin 310 and notches 312, 313 have the relative positionsdefined as described above. When, therefore, a cassette is inserted intothe tape recorder 10 without pressing the push lever 290 to release thelocking mechanism 20 and the movable chassis 16 is lifted by the urgingforce of the tension spring 270, then the engagement pin 310 is insertedinto the notch 312. Under this condition, the erase head-fitting board304 is rotated counterclockwise by the urging force of the tension coilspring 300. The erase head 44 which is retracted at this time does notabut against a tape. Therefore, it is possible to carry out only thereproduction mode, but not the recording mode. If, under this condition,an attempt is made to press the push lever 290 by mistake, theengagement pin 310 of the push lever 290 is inserted into the notch 312,thereby preventing the push lever 290 from being pressed. Consequently,the erasing of a tape which might otherwise occur by erroneous operationduring reproduction can be completely prevented. As mentioned above,reproduction alone can be carried out under normal conditions. Recordingcan be effected only by pressing the push lever 290 to push the erasehead 44 for contact with a tape. For the recording mode, the push lever290 is pressed for the prescribed distance, that is, until the pins 295,296 respectively abut against the right side walls of the elongatedholes 292, 293 against the urging force of the tension coil spring 300.Where the movable chassis 16 is lifted by inserting a cassette in thetape recorder 10 with the push lever 290 pressed, then the engagementpin 310 is inserted into the notch 313 of the movable chassis 16. If, atthis time, the push lever 290 is pressed backward, then the bentattachment 311 is also retracted. As a result, the urging force of thetorsion spring 308 is given a full play, causing the head-fitting board304 to be rotated clockwise about the rotation center 306 (FIG. 21).Accordingly, the erase head 44 is set in the prescribed projectingposition for contact with the surface of a tape, thereby effecting itserasure. The angle through which the head-fitting board 304 is rotatedclockwise to determine the prescribed projecting position of the erasehead 44 is defined by a bent stopper 314 (FIG. 1) extending above thefixed chassis 14. This stopper 314 also acts as a member against whichthe other end of the torsion spring 308 is pressed.

If required recording on one tape surface is brought to an end after thecompletion of recording on the opposite tape surface, the automaticreverse operation of the tape recorder some times gives rise to thepossibility of a recorded data, for example, a music piece being erased.To avoid such undesirable event, it is preferred that a normally closedswitch 315 (FIGS. 20 and 21) which is rendered nonconducting when thepush lever 290 is pressed to set in the plunger drive circuit 106. Ifthe push lever 290 is pressed for the recording mode, then theprojecting attachment 317 of the push lever 290 is jointly moved inwardto abut against the movable contact of the normally closed switch 315 todetach it from the fixed contact, thereby opening the plunger-drivingcircuit 106. When the plunger-driving circuit 106 is opened, then anautomatic reverse tape run is made impossible, thereby preventingrecording from being effected on the opposite side of a tape.

Generally, a reliably accurate vertical level of a tape is ensured onthe A plane of a cassette, whereas the level can not be realized on theB plane thereof. With the foregoing embodiment of this invention,forward recording is made possible only when a cassette is inserted intothe tape recorder 10 with the A plane kept upward. At this time,recording can be effected with tones of good quality. It is considerednecessary to stop the operation of a program switch during the recordingmode. To this end, it is possible to fit, for example, a program switch305 to the push lever 290 and attach the program button 301 to the fixedchassis 14 for abutment against the program switch 305 (FIG. 22). Thepush lever 290 projects outward during the reproduction mode and ispressed inward during the recording mode. The program button 301 is somounted on the fixed chassis 14 as to abut against the program switch305 set on the push lever 290 only during reproduction, by utilizing theabove-mentioned arrangement of the push lever 290. The program switch305 is of the normally closed type. A compression spring 307 is woundabout the shaft of the program button 301. The program switch 305 is sofitted to the push lever 290 as to be moved with the push lever 290beyond the range of the depression stroke of the program button 301. Theabove-mentioned arrangement prevents the program button 301 frompressing the program switch 305 while the push lever 290 is pressed.Since, at this time, the program switch 305 is not actuated, theexecution of a program (manual reverse operation) can be completelyprevented during recording.

Since recording is undertaken only during the forward run of a tape, thehead 28 may obviously be the type exclusively used for reproduction,instead of the concurrent type for both recording and reproduction.

The fast forwarding of a tape is required during reproduction but isunnecessary during recording. Therefore, the stopper board 316 forpreventing the rotation of a tape FF lever 42 during recording ismounted, as shown in FIG. 1, on the fixed chassis 14 close to the tapeFF lever 42. As apparent from FIG. 23, the stopper board 316 compriseselongated holes 320, 321 into which the smaller diameter sections of thestepped pins 318, 319 mounted on the fixed chassis 14 are looselyfitted. The stopper board 316 is provided at one end with a cam groove326 into which there is loosely inserted a guide pin 324 mounted on thepush lever 290 for changing over the operation of the erase head. Theother end of the stopper board 316 constitutes a stopper attachment 328extending close to a pin 224 for defining the rotation of the tape FFlever 42. The stopper board 316 takes the position indicated in FIG. 23during the reproduction mode in which the push lever 290 is not pressed,because the guide pin 324 and cam groove 326 of the stopper board 316are engaged with each other. Under this condition, the stopperattachment 328 is removed from the pin 324. During the recording mode,however, in which the push lever 290 is pressed to push the erase head44 for contact with a tape, the stopper board 316 is moved upward ofFIG. 23 to allow for the movement of the guide pin 324 resulting fromthe pressing of the push lever 290. In other words, as the guide pin 324travels through the cam groove 326, the stopper board 316 undergoes anupward acting component of force, and occupies the position shown inFIG. 24 by being guided upward by the pins 318, 319. The distancethrough which the stopper board 316 is to be moved upward is determinedin consideration of the shape of the cam groove 326 so as to allow thestopper attachment 328 to move vertically through a space lying ahead ofthe pin 224. When the push lever 290 is pressed, the attachment 328 ofthe stopper board 316 protrudes toward the pin 224 and is positioned onthe rotation path of the pin 224. If, therefore, an attempt is made torotate the lever attachment 212 in any direction, the lever attachment212 can not be rotated, because the pin 224 abuts against the stopperattachment 328. Consequently, it is possible to completely stop the fastforwarding of a tape which might otherwise occur by erroneous operationduring the recording mode.

In FIGS. 1 and 23 to 25, reference numeral 332 denotes a movablelocating pin which sets a cassette exactly in the prescribed position inthe tape recorder 10 with the aid of locating pins 333, 334. Thismovable locating pin 332 is fitted to a rotatable support board 336above the fixed chassis 14, and is urged inward by a torsion coil spring340 wound about the pin 338 mounted on the fixed chassis 14. Referencenumeral 342 denotes a pin against which the other end of the torsionspring 340 abuts. When engaged with the guide hole of a cassette, themovable locating pin 332 presses the cassette inward and is of doubleconical form in order to push the cassette further inward even afterbeing fully engaged with the guide hole of the cassette. The locatingpins 333, 334 mounted on the fixed chassis 14 are similarly of doubleconical form.

A main switch 344 for supplying power to a print circuit formed on aprinted circuit board (not shown) mounted on the fixed chassis 14 isfitted, as shown in FIGS. 26 and 27, to the lateral wall of a bentattachment 346 extending downward from the fixed chassis 14 (extendingupward as indicated). The main switch 344 comprises a fixed contact 347and movable contact 348. The movable contact 348 is adapted to beremoved from the fixed contact 347 under normal condition. The movablechassis 16 has an inwardly extending bent attachment 350. At the fall ofthe movable chassis 16, the movable contact 348 does not touch the bentattachment 350, but is removed from the fixed contact 347 due to itsintrinsic property. At the rise of the movable chassis 16, the movablecontact 348 is so moved as to abut against the fixed contact 347 bymeans of the bent attachment 350. When, therefore, the movable chassis16 is lifted by the insertion of a cassette into the tape recorder 10,then an electric circuit is established on the printed circuit board. Asa result, a motor is driven to let a tape run in the forward direction.

FIG. 28 shows a case 218 for receiving the fixed chassis 14, movablechassis 16 and other members. A cassette is inserted into the taperecorder 10 through an inlet 356. A large number of openings are formedin the front wall of the case 218. Reference numerals 358, 360, 362denote openings for the push button 252 of the engagement lever 242, thelever attachment 212 of the tape FF lever 42 and the push button of thepush lever 290. Triangular windows 364, 366 show the display windows ofthe lamps indicating the directions in which a tape is running at aparticular time. Reference numeral 368 indicates an opening for theprogram button 301 for the program switch 305 used to reverse therotation of the motor 24 as often as required, instead of at the momentwhen a tape end is detected.

The case 218 is formed of a pair of halfcases 372, 374. The upperhalfcase 372 comprises, as shown in FIG. 29, a pair of guide attachments376, 377 for guiding a cassette when inserted into the tape recorder 10.Each of the guide attachments 376, 377 has a pair of engagement holes.Pins 378, 379 erected on the upper halfcase 372 are fitted in the pairedengagement holes of the guide attachment 376. Pins 380, 381 erected onthe upper halfcase 372 are fitted into the paired engagement holes ofthe guide attachment 377. The guide attachments 376, 377 are fixed tothe upper halfcase 372 by means of the pins 378 to 381. As seen fromFIG. 29, the guide attachment 376 has a crosswise bent member 383, andthe guide attachment 377 has a crosswise bent member 384. The lateralposition of a cassette is guided by the joint action of the lateral wall386 of the guide attachment 376 and the end wall 387 of the guideattachment 377. The lower position of the cassette is guided by theupper surface 388 of the bent member 383 of the guide attachment 376 andthe upper surface 389 of the bent member 384 of the guide attachment 377(the surfaces are directed downwards as indicated). The upper positionof the cassette is guided by the urging force of a torsion coil springof a hinged inlet cover (not shown) rotated upward by the insertion ofthe cassette, the urging force being applied to the cassette from above.The guide attachments 376, 377 and inlet cover can guide the cassettesubstantially to the prescribed position, although the guiding may becarried out roughly. The accurate location of the cassette is effectedby the double conical fixed locating pins 333, 334 and movable locatingpin 332. The above-mentioned rough guide of the cassette by the guideattachments 376, 377 and inlet cover is carried out without using themembers mounted on the fixed chassis 14, whereby ensuring the desiredguide of the cassette by a small number of parts without complicatingthe construction of the tape recorder 10 itself.

FIG. 30 is a block diagram showing the operation of an FF switch andprogram switch. When the FF switch is actuated, a head signal generatedin the logic circuit 104 is cut off, causing the motor 24 to be fastdriven in the forward direction. When the program switch 305 isoperated, then a head signal produced in the logic circuit 104 is cutoff, causing the motor 24 to be fast rotated in the opposite direction.When the program switch 305 is released, then the plunger is again putinto operation to start the normal rotation of the motor 24.

FIG. 31 is a block circuit diagram of the automatic reverse stop switch315 for stopping the automatic reverse operation during recording.

According to this invention, one end of the tape FF lever, when rotated,is engaged with the pinch roller-supporting board for its rotation,thereby retracting the pinch roller to a position where it does notcontact a tape surface. Engagement between the tape FF lever and pinchroller-supporting board ensures the FF or REW lock. This inventionenables the FF or REW lock to be easily effected by the rotation of thetape FF lever without increasing the number of parts used. In otherwords, the FF or REW lock can be sustained even when the operator takeshis hand off the tape FF lever. When the FF or REW operation proceeds tothe end of a cassette tape, the FF or REW lock is easily released byactuating the automatic reverse plunger for the rotation of the pinchroller-supporting board, to disengage it from the tape FF lever, therebysaving the tape recorder from requiring a complicated arrangement.

What is claimed is:
 1. A tape recorder which comprises:a pinchroller-supporting board rotatable about a rotation center and one end ofwhich carries a pinch roller; a capstan shaft; a rotatable tape FF leverfor actuating an FF motor switch to carry out fast forward or rewind runof a cassette tape, regardless of the direction in which the tape FFlever is rotated from a neutral position, the tape FF lever beingprovided with an engagement member which is engaged with the pinchroller-supporting board for its rotation regardless of the rotatingdirection of the tape FF lever, thereby retracting the pinch roller froma position in which the pinch roller clamps a cassette tape with the aidof the capstan shaft; the tape FF lever being locked in the rotatedposition by engagement between the pinch roller-supporting board and theengagement member, and urging means for urging the pinchroller-supporting board about the rotation center, and which, when theengagement member of the tape FF lever is engaged with the pinchroller-supporting board, lock the tape FF lever in the rotated position.2. The tape recorder according to claim 1, which further comprises:tapeFF lever-locating means for urging the tape FF lever to the neutralposition.
 3. The tape recorder according to claim 1, wherein the urgingmeans includes a torsion coil spring wound about the rotation center ofthe pinch roller-supporting board.
 4. The tape recorder according toclaim 3, wherein the engagement member of the tape FF lever is a pinfitted to one end of the lever, the pinch roller-supporting board has anotch formed in a lateral wall of an end portion of the board, and whenthe tape FF lever is rotated, the engagement member of the tape FF leveris engaged with the notch.
 5. The tape recorder according to any one ofclaims 2 to 4, wherein the tape FF lever-locating means includes asubstantially triangular hole provided in the tape FF lever and having awall defining an apex, two corners and a base portion therebetween, apin fitted to the free end of a rotatable coupling board and extendingthrough the substantially triangular hole, and an urging member forurging the pin toward the apex of the triangular hole, thereby holdingthe tape FF lever in a neutral position; and the tape FF lever isrotated against the urging force of the urging member, and the extent ofthe rotation of the tape FF lever is defined by the abutment of the pinof the tape FF lever-locating means against the wall of either corner ofthe base portion of the triangular hole.
 6. The tape recorder accordingto claim 5, including a motor FF switch having a pair of fixed contactsand one movable contact disposed therebetween, the tape FF lever beingprovided with an elongated groove into which a forward end of themovable contact of the motor FF switch is loosely inserted, and when thetape FF lever is rotated in either direction, the movable contact ispressed against one or the other of the paired fixed contacts to renderthe motor FF switch conducting.
 7. The tape recorder according to anyone of claims 1 to 4, which further comprises a rotatablehead-supporting board rotatable about a rotation center and whichsupports a pair of magnetic heads on both sides of the rotation centerof the head-supporting board and is so disposed as to face the pinchroller-supporting board; and wherein the pinch roller-supporting boardincludes a pair of engagement attachments, which, when the tape FF leveris rotated in either direction from the neutral position to rotate thepinch roller-supporting board, abuts against the head-supporting boardon either side of the rotation center thereof to rotate thehead-supporting board in the corresponding direction about the rotationcenter, thereby retracting the magnetic head from a tape surface.
 8. Thetape recorder according to claim 7, wherein the engagement attachment ofthe pinch roller-supporting board is a bent portion integrally formedwith the pinch roller-supporting board at that end thereof at which thepinch roller is supported.
 9. The tape recorder according to any one ofclaims 1 to 4, which further comprises:a rotatable head-supporting boardhaving a rotation center and carrying a pair of magnetic heads on bothsides of the rotation center of the head-supporting board; a plungermechanism which is provided with a plunger driven when a cassette tapeis taken up to the end, and rotates the head-supporting board when theplunger is driven; and a rotatable plunger arm which connects theplunger and pinch roller-supporting board together, and, wherein whenthe plunger is driven when the cassette tape is taken up to the end, theplunger rotates the pinch roller-supporting board about the rotationcenter thereof against the urging force of the urging means, therebyreleasing the pinch roller-supporting board from the engagement memberof the tape FF lever.
 10. The tape recorder according to claim 9,wherein the plunger arm is provided with an elongated groove into whicha pin fitted to the plunger is loosely inserted and another groove intowhich a separate pin fitted to the pinch roller-supporting board isinserted; and wherein when the plunger is driven when a cassette tape istaken up to the end, the plunger pin is carried through the elongatedgroove up to the end to cause the plunger arm to be rotated about therotation center of the pinch-roller supporting board, thereby effectingthe rotation of the pinch roller-supporting board by means of the pinthereof.
 11. The tape recorder according to claim 5, which furthercomprises:a rotatable head-supporting board having a rotation center andcarrying a pair of magnetic heads on both sides of the rotation centerof the head-supporting board; a plunger mechanism which is provided witha plunger driven when a cassette tape is taken up to the end, androtates the head-supporting board when the plunger is driven; and arotatable plunger arm which connects the plunger and pinchroller-supporting board together, and, wherein when the plunger isdriven when the cassette tape is taken up to the end, the plungerrotates the pinch roller-supporting board about the rotation centerthereof against the urging force of the urging means, thereby releasingthe pinch roller-supporting board from the engagement member of the tapeFF lever.
 12. The tape recorder according to claim 11, wherein theplunger arm is provided with an elongated groove into which a pin fittedto the plunger is loosely inserted and another groove into which aseparate pin fitted to the pinch roller-supporting board is inserted;and wherein when the plunger is driven when a cassette tape is taken upto the end, the plunger pin is carried through the elongated groove upto the end to cause the plunger arm to be rotated about the rotationcenter of the pinch-roller supporting board, thereby effecting therotation of the pinch roller-supporting board by means of the pinthereof.
 13. The tape recorder according to claim 6, which furthercomprises:a rotatable head-supporting board having a rotation center andcarrying a pair of magnetic heads on both sides of the rotation centerof the head-supporting board; a plunger mechanism which is provided witha plunger driven when a cassette tape is taken up to the end, androtates the head-supporting board when the plunger is driven; and arotatable plunger arm which connects the plunger and pinchroller-supporting board together, and, wherein when the plunger isdriven when the cassette tape is taken up to the end, the plungerrotates the pinch roller-supporting board about the rotation centerthereof against the urging force of the ruging means, thereby releasingthe pinch roller-supporting board from the engagement member of the tapeFF lever.
 14. The tape recorder according to claim 13, wherein theplunger arm is provided with an elongated groove into which a pin fittedto the plunger is loosely inserted and another gr-ove into which aseparate pin fitted to the pinch roller-supporting board is inserted;and wherein when the plunger is driven when a cassette tape is taken upto the end, the plunger pin is carried through the elongated groove upto the end to cause the plunger arm to be rotated about the rotationcenter of the pinch-roller supporting board, thereby effecting therotation of the pinch roller-supporting board by means of the pinthereof.